Connect to Zoom API with Apps Script and OAuth

The following blog post is about connecting to the Zoom API by creating a Zoom OAuth App and then using a Web App designed in Google Apps Script. Our aim here is to return an Access Token which could then subsequently be used to access Zoom account data (eg your profile, meetings, etc).

Here are some useful links:

• How to create an OAuth App in Zoom.
• Zoom App Marketplace.
  
• How to deploy a Google Apps Script as a Web App.
  

 

Process overview

There are a set of steps that we need to complete in order to achieve successful authentication (connection with our Zoom account via the Zoom API):

1. Have a user visit a dedicated URL (which comes from our Web App).
2. This URL is attached to our Zoom OAuth App and upon a user visiting, it returns an Authorisation Code.
3. Our Web App then uses this Authorisation Code along with the Client ID and Client Secret (generated when we created the Zoom OAuth App) to make another request that finally returns an Access Token, valid for 1 hour.
4. Further blog posts will explore how we then get Zoom account data, create meetings, etc with the Access Token.
   

Creating the Web App

You will need to follow these instructions to deploy a script as a Web App, from which you will get a URL that will be connected to your Zoom OAuth App. Whether you do this before or after implementing the below code is up to you.

We begin with the Function that is called when a user visits the given webpage - 'doGet(e)' - which captures the HTTP request. The 'e' contains an event parameter (the Authorisation Code in this instance) that we want to extract from the URL:

// get authorisation code from returned Url
var authCode = JSON.stringify(e.parameter.code);
// remove quotes around the code
var authCodeClean = authCode.replace(/['"]+/g, '')

There is also a regular expression used above to remove the set of double quotes from the returned value (the Authorisation Code) as these double quotes will interfere with the next step if they are left in place.

Next we're ready to call the getToken Function, into which we pass the Authorisation Code. First we define the necessary authentication required by the Zoom OAuth App:

// set authentication and get OAuthKeys
var clientID = "ENTER YOUR APP ID HERE";
var clientSecret = "ENTER YOUR APP SECRET HERE";
var encodedKeys = Utilities.base64Encode(clientID + ":" + clientSecret);

//Set the HTTP headers
var options = {
  'method': "post",
  'headers': {"Authorization": "Basic " + encodedKeys},
};

Now we can make the call to the Access Token URL as specified by the Zoom documentation:

// Web App URL linked to Zoom OAuth App
var returnUrl = "ENTER YOUR WEB APP URL HERE";

// make Zoom OAuth call
var response = UrlFetchApp.fetch("https://zoom.us/oauth/token?grant_type=authorization_code&code=" + authCodeClean + "&redirect_uri=" + returnUrl, options);

Lots of information is returned so the final step we perform is to extract the Access Token specifically:

// run Function to extract Access Token
var resultText = response.getContentText();
var resultObj = JSON.parse(resultText);
var accessToken = resultObj['access_token'];

It is from this point here that we can now make use of the rest of the Zoom API as we have authenticated our account for access. I will look to cover this in the next couple of blog posts.

 

Creating the Zoom OAuth App

In conjunction with the above we need to have a Zoom OAuth App setup and linked to the Web App. Use these instructions to create the Zoom OAuth App. A couple of points about the one I created:

• It is a user-managed app, meaning it is installed and authorised by users individually.
• The 'Redirect URL for OAuth' is the URL for your Web App. I replaced the 'exec' at the end of mine for 'usercallback' instead
• Turned off 'Event Subscriptions'.
• Scopes: meeting:read, meeting:write, user:read, user_profile
  

Once you are happy and have completed the necessary information you can try visiting your Web App URL, authorise your account with Zoom and then capture your Access Token.

File Download

Download the Zoom API with Apps Script and OAuth here. Please use 'File' > 'Make a copy' for your own version. This is a Google Sheet with the Apps Script bound to it. You will need to deploy it as a Web App and create your own Zoom OAuth App.